He's teething. You need to get him chew toys because you don't want him to get in the habit of biting you or furniture, shoes, etc. If one doesn't work, try a different one. Dogs are like people and different dogs like different things.
When he bites you, reprimand him. Slap him with a rolled up newspaper or something. I have many pets, and biting is an ABSOLUTE no no. My pets get slapped right after they do it. I only condone hitting an animal when they do something I consider terrible. This is one of those instances.
roll him over on his back,hold his mouth closed with you thumb & forefinger and yell NO! keep doing this when he starts biting you & be consistent and he will get the message. Please dont hit your dog with a rolled up newspaper-that will make him aggressive.just smacking the paper against your hand is enough to get a dog to stop & pay attention-the sound gets them to notice. remember all puppies have a very short attention span- sort of puppy A/D/D